Mr Kennett said people in Melbourne were "just scared" and those in power "don't want to put at risk popular support".

"Bob Carr stood up to those sorts of criticisms, introduced the Sydney safe injecting facility, and it has been highly successful both for those who use it and for the community around it," Mr Kennett said.

Injecting rooms outdated, Government says

A spokesperson for Victorian Mental Health Minister Martin Foley told The World Today that injecting rooms were "based on 1990s ideas".

"The debate for safe injecting rooms failed to win support 10 years ago when heroin deaths rivalled the road toll," the spokesperson said.

Fatal heroin overdoses are now a fraction of what they were in the 1990s.

Associate Professor Craig Fry from Victoria University told the ABC's Bonny Symons-Brown there was an argument that money spent on an injecting room trial could be better used to improve existing drug services.

"It's about assessing these sorts of issues in the context of what the current illicit drug market is, what are the patterns of harm we're seeing from that, and really being able to tailor our policy responses rather than automatically and uncritically assuming that an injecting centre is always going to be the best policy decision," he said.